Have you ever seen Spotify? It's completely free and absolutely superb. I *think* it might be only UK accessible at the moment, but I'm not sure.
Anyway, try this link - it will definitely work in the UK. You will need to download 'spotify' but it's completely free. The link for my soulful selection including Tower of Power, Mary J Blige, Jamiroquai, Dusty Springfield and loads of others is at this link here
If you can access it, have a listen and let me know what you think!